The river is so tremendously blissful because it knows it is going to the ocean. At the ocean it appears on the one hand as if the river has disappeared, but in fact only the banks disappear - the river remains. And the banks are a bondage. The river was dancing, but its feet were chained.
Those banks were its prison. The dance will remain, will become freer - so vast that perhaps you cannot see it, because the river is not going to disappear; it is going to become the ocean.